Hi James, I would make two suggestions. One, attach your drill to the rotor shaft and turn it slowly that way, then use some 400 or 600 grit wet and dry paper on the slip rings. That way you'll get the grooves flattened out. Follow up with your scotchbrite. As to why these failed it's the material used for the brush holder. It needs to be Bakelite or a similar material. The plastic they've used is too easily melted by heat. They will fail again. Running 3000 watts from these is too high. Despite being listed as 3200 watts that would be for a very short duration. Somewhere it probably lists 2500 or even 2000 watts as the continuous power. Just my observations. Thanks for the video.

I had a thought when you were cleaning up the slip rings: When you have a bad rotor, you might cut up the slip rings and find out how thick they are. If they are relatively thick the next time this happens you can use something more aggressive (grades of emery cloth) to make sure the rings are really smooth. Another excellent video. Thanks!

I've watched hours and hours of your videos, and you've educated me not to be scared of pulling these apart. Bought two gennies both none runners and them working within half an hour, thanks to your tutorial. One I had to dial in the running speed to get the voltage where it was right.

Something else to check there. I've had that same fault occur with a certain brand (looking otherwise identical) where the ball bearing in the tail housing had started to spin. The bearing itself was still ok, but the outer race spinning had allowed a small clearance to develop, probably loosening when the case metal heated up in use. That clearance then allowed the rotor and slipring to chatter which caused the brushes to bounce and arc, and then overheat. Replacing just the brushes became a temporary fix before discovering this. Your slipring shows the same chatter marks. I found a loctite bearing retaining compound that cured the problem, I also pulled the bearing itself back slightly on the shaft, that allowed it to index on the original bore while the loctite filled the remainder. None have come back since adding this repair to the original brush replacement. An alternative would be to over bore and sleeve the housing, if I was doing my own (with no cost limit) I'd do it that way. Cheers.

Pretty crazy both generators had the exact same brush failure, probably just poor quality manufacturing, nice work James!

It is so wonderful to see someone who knows what they are doing. It's a good feeling!

Watching your videos helped me on the weekend power went out had to clean carb on generator even though I ran it out of gas and drained the float bowl. Thanks

You said it at the end, James. Either bad brushes or bad slip rings. Using substandard brushes is easily remedied. Substandard slip rings are a life-limiting flaw that will finish off a good rotor before its natural life comes to an end. We all bemoan poor quality components in our products do we not?

James, you are a master. I'll probably never stick my hands in a power head, but I thoroughly enjoyed watching you. I know I could if I had to. You're so knowledgeable and calm.

This fix works for me. But I know very little about generators so all I can say is great information for me. I think the customer will be very pleased even if the brushes have to be changed again. Thanks for the videos.

A thought about not having the light on. Once I thought I made a mistake, but then I realized I was wrong! Always a wonderful feeling when you realize you were really right!

Good job(s) Jim, I take it you have been assembling a database of parts used, ohms readings and failures encountered. At this point your knowledge base must be getting quite extensive. Keep up the good work and enjoy the holiday.

Nice job as always. Never would expect any less from you. Thank you once again. Love and blessings!

James, the reason why those brushes failed so quickly is because of them being misaligned onto the slip rings. I'll send you a private message with a picture describing what I'm talking about but you may want to use an inspection camera to make sure the brushes are sitting directly on top of the rings. If only a portion of the carbon brush is on the slip ring it creates a bottleneck for the current to go through thus why it got hot.

What are the odds of getting two identical generators with identical issues that are identically easy to repair? Lol that’s awesome, great job!

Very educational. As an aside, I had a royal pain on a Hyundai HY7000 that was a nightmare from day of purchase (in fact the genny was 4 years old when "new") that would not start after 2 years of having to replace all sorts of bits that simply failed, like the tank float, the fuel valve, both wheels at different times, the digital display module (which has failed again.. Turns out the internal coil cell has run flat.. The module is No Longer sold as a spare part), It has run less than 20 hours in the 6 years I have had it. Turned out the latest starting issue was the magneto as it never ever started on the cord and was reluctant on the electric start. Now, for the first time ever, it starts on the cord. Shout out to generator Guru in the UK for having the spares Hyundai after sales in the UK said were unobtainable.

Very interesting video. I've repaired several privately owned small engined generators and compressors that had failed due to neglect or misuse, but have not had to replace the brushes, luckily, as the suppliers of these (mostly Chinese made) machines in the UK do not always (if at all) carry spare parts. At the power station where I worked, some of the small motor generators suffered from sudden commutator sparking and had to be taken off line within minutes to avoid a reactor trip (scram), but to avoid skimming the commutator in the workshop, a hand held abrasive stone (these were actually sold for the purpose of brush bedding) whilst running at full speed worked wonders. Slipring brushes on the main 52MW turbo alternators were changed on load with care. The exciter commutator brushes were changed whilst shut down, although I did once do it on load- not for the faint-hearted and certainly not done routinely.

Another problem that can happen with these kinds of generators is they become degaussed and need to be flashed. These generators don't have permanent magnets, they depend on electromagnets to provide the static field that the rotor field moves through, to generate power. There's usually a small bit of magnetism in some iron that provides enough of a field for it to start generating a bit of power for the static field coils, which then provides a strong enough field for the generator. What happens is sometimes that bit of magnetic iron gets degaussed (ie. all magnetism removed from it), so it is no longer magnetic, so the generator can't start generating power to generate a field which then makes the main power. The way this usually happens is if you turn the motor off while the generator has a load attached, or if it runs out of fuel with a load attached. You should never start or stop a generator when it's under load, because of this. The way to fix it is to "flash" the generator. You can do this by either using a car battery to put a short pulse of current through the coils WHILE the generator is running (connect and disconnect it really fast between the active and neutral of the generator output). Another potential way is to have a corded power drill plugged in while the generator is working (but not generating power), then quickly spin the drill - the idea is that spinning the drill will induce enough current in the generator's coil to provide a start field for the generator. I found the car battery method to be the most reliable, but it is dangerous - you only want that to be connected for a very very short time. There's a few youtube videos on "flashing" a generator which probably explains it better than this.

Thank you sir for all those clearly articulated videos. Have a great day.

I’ve been watching your videos since I became a subscriber and you are talented with these generators. It’s really something how resilient these are. I’ve seen some basket cases that you’ve done and you bring them back to life and in most cases better than factory. It’s great that you can sell these at a decent price to help people out. Grady job bud. Thank you for sharing your talent. I’ve been a mechanic for over 40 years and I’m learning a lot watching your videos. Thank you

these were such a mystery to me, one of the few electrical things I wouldn't work on, thanks for demystifying them for me

When you said you wanted to ‘scotchbright’ the slip rings - I thought you were going to drive the generator shaft with a socket in a battery drill - I love the meticulous diagnosis on your channel - good watch!

Thanks for giving us something to watch, and a happy ending to boot.

Hi James! Thank you for your videos! For some reason, I am sitting and watching them all :) despite I got nothing to do with world of mechanics. I even fixed my Generac 5500 according to your instructions, believe me or not. Keep it up please !

My neighbor has this exact machine. About 18 months ago we had a bad ice storm and power was out for 12 days. About day 5 he brought it to me with this exact problem. I buffed the slip rings heavily and works great

James you get the great deals at very good price and at low cost repair. Enjoy looking for next post. Michael.

Great video. What a coincidence getting 2 exact same units. Made for some good footage.

...James....outstanding DIY tutorial......video and audio quality are first class....thanks for posting... :)

This is very helpful, at a garage sale or at the thrift-shop I will only look for brushless generators.

Amazing outcome James thanks for sharing 🦘👍

A fun twofer for a Thursday morning. I think this is the first video of yours with melted bush holder. Something I'll have to keep in mind if mine ever fails. It may just been me but the second genie sounded like it was hunting.

You can also put high temp graphite lube on the brush blocks where they slide in and out of the plastic holder so they mate up smoother with the slip rings.

Hi James great class mate nice to see you had twins with the same problems and a easy fix Its great when it works out that simple Keep up the good work James

Beautiful , and the comments are also helpful . Can we conclude that operating the generator in cold weather conditions will ease the overheating problem which caused the crap plastic to deform ? Also leaving the cover off will help to keep it cool maybe. Fixing the arcing problem somehow might be the solution like having capacitors shunting the brushes in the fashion of old school points capacitor for old school automotive ignition systems .

Another fascinating video where I learned something. Great job.

Wow, what's the chances of 2 generators of the same make & model falling in your lap & both having the same problem... And a fairly easy fix too! I wonder if it would make sense to clean up the slip rings with a little emery cloth first & then polish them up with the scotchbrite pad obviously making sure to clean any grit off them when done. I've used this method on automotive starters without any problem. Nice job checking these out & quickly getting to the root of the problem!

Thank you for an excellent explanation. I have the exact generator. It hasn't failed yet, but it is good to know where to look.

Good man yourself. I learnt a couple of things today. Much appreciated.

James just another great video thanks looking forwards to the next one 👍

Crazy well done James ! John from the UK

Easy fix and a cheap 8 dollar part. I love those. Wish all my repairs were that easy.

A small narrow honing stone, to clean and smooth the brushes, i do this with the engine running, After honing i use a piece of hardwood to burnish the slip rings, this removes any scratches and helps prevent arcing by creating a surface on the slip ring that is equal resistance any point overall surface, no arcing

You must live in a magical place to be able to find these gensets. I'm always looking and never seem to many.

Gotta say the truth, you are good. I wish I had you up around my neighborhood make some good money.

I Googled the brushes after you diagnosed the 1st one and found it interesting that they're so omnipresent on the internet,,,, must be a chronic issue over many makes and models...

Thank you for the video I have been learning more every vidoe. You are a great narator and you are very meticulous person which it makes it easy to learn.

Thank you, I was looking for a video like this, a how to clean up the brushes!

WoW! Great JOB... AGAIN!!!

Good man. Pencil erasers, are a very fine soft abrasive. We used them, for over 30 years, cleaning memory sticks/chips on computers. And any other electronic/electrical , type of similar. The white, rectangular ones, work very well, also. As do sandpaper sticks, for larger metal objects.

Thanks for the video Jim 🙂

very much interesting, thank you.

That was interesting, you take the mystery out of these generator s. Thanks

Thanks for the update

thank you James, very informative

this is a welcome change from the usual carby cleaning video

your videos are always SUPER ! thank you

at 10:35, I would've spun the rotor using a socket attached to a power drill to turn it, while using a 400-800 grit sand paper to shine the brass rings.

Congratulations on your "twins," Jim. Who knew that they would have the same problems. I passed up two generators at a local scrap yard. One was missing the carburetor, and the other one I didn't get a close look. The first was a rebadged champion unit. I suppose that they both could have been repaired given the fact that it seems that they were scrapped by an electrical contractor who was either closing down, or maybe just cleaning up the tool room. I got two ridgid 24" pipe wrenches, and they were fine, one forged steel and the other one aluminum, and the corded tools in their metal cases likely were fine too, though they appeared to be a bit older, like the Black and Decker reciprocating saw. It's a shame there is so much waste. I had my car this day and didn't want to mess up the seat, so I passed on the generators.

This is the time where a 2nd body would be nice. 1 to pull the pull starter and 1 to hold the scotchbright . Great video

Nice Job Jim! 👍😎

Great tip James

Great vid's....very,very informative and helpful!👍

Held me in suspense in that second one. Dang light switch 🤣

Hello James, your video is very interesting, acquiring two equal generators with the same problem, suggests that the quality of the constriction of the brushes and of some elements, may be of inferior quality... thanks for your videos and the teaching to analyze and solve these types of problems... thanks... a big greeting from Puerto Rico 🇵🇷...

👍🏼✌🏼thanks for the video. Very informative

Thank you, well done!

We've seen this problem before, and it's almost always been on generators which weren't given any 'run down' time after running on a full load. It shouldn't happen at all, but it always seems to be on machines that have been hot, and not allowed to cool down before stopping. Another scenario might be on machines that have been overloaded, long enough to overheat, but not enough to cause a failure. Looking at those slip rings though, it seems evident that the machining leaves a lot to be desired.

5.26.22 Another fine video James. I also looked at the video from Bassguitarist1985 on his pictures of the alignment. Good stuff. Thanks

Thanks for the video

Well done!

Thanks for the vid James.

I've "fixed" so many old generators by doing the drill trick. Just plug in your drill and hold the button then grab the chuck and twist real good. Literally every time someone seen me do it they were in just disbelief lol 😂 like yep I'm a sorcerer I have lightning in my fingers

I like using a model train track cleaner. They are called bright boys and they are a gritty eraser. They do the best polishing and deep grooved resurfacing.

Wow ive never seen you load one up that close to maximum rated power. 👍

Great video as always, I'm thinking white sapphire is on to something but it could have been a combination of factors

Great, really enjoyed your video

great job. you made it look easy.

I think it is the resistance between brush and slip ring that will give more potential divergence between the two. So you get voltage between the two and amps over the two making wattage. Wattage becomes heat and melts the brush holder.

This is just like your "double trouble" video from way back. 😃😃👍👍 Glad that it was an easy fix. But come on Jim ....only 24 mins? 😂 Looking forward to next week. Thanks as always for excellent content.👍👍😃😃

Awesome video and very well explain regarding how to tennical away a like that thank you for the great tutorial video we appreciate it

Another great fix.

I've heard of the capacitor being faulty and not storing enough to excite the armature windings, the machines you fixed must have had defective brushes from the factory if they weren't able to clean those rings through use. Good diagnosis.

Jim: I learn a lot from your clear explanations and I might even tackle a job like this if I came across the opportunity. I have the engine side down. It is the generator side that I am learning from your content. Thank you. Do your space heaters ever get used to heat spaces, or are they basically for the purposes of providing known load for testing generators?

Very useful. Thanks.

I have Troy-Bilt 8000 watt, brush slip rings got dirty from sitting. For that one I started engine and used a fine sand paper held against the slip rings. Brush holder was not impeded with wires or other things in the way so was pretty safe to do that. Worked fine after simply cleaning. I think after sitting for a few years, the copper corroded on the slip rings.

really, really cool. excellent video. very helpful.

Top video again James!

I noticed that they only use one of the possible two bolts to hold the brush carrier - a few cents saving that could allow the brushes to mis-align and cause the heating and failure. But my bet would be poor initial quality of the slip-ring surface which adds to the one-bolt problem in causing brush heating. Drill and tap for that second fixing bolt!

Thanks for the great video as usual James. I look at it as a quality control issues that made the components at the factory or they sat and accumulated the corrosion? At any rate thanks for the almost tear down. Ed

thanks, another great video

Yea those cheap imports, lucky that both work again, easy fix great video

Very nice video learned a lot keep up the good work.

Great and informative video!

good troubleshooting!

The material the brushes are made from changes the resistance and causes heat build up.. the higher the resistance the higher the temp... good brushes DO NOT GET HOT and the brush holders dont melt.. you can measure the resistance of the brushes.. ALL GENERATORS ARE NOT CREATED EQUAL... you get what you pay for...I would not spend my money on something like that..GREAT VIDEO !

I would agree with other people, a bad quality slip ring can course the problem for the brushes. Also that light being off scared me TOO. Shame on you. 🤣 It was funny to me. Thanks for the video and have a great day.

Excellent troubleshooting. I like that. Did you order brushes online or did you have a pile of spare parts laying around. Thanks for sharing

Will keep that in mind if my generator quits thanks👍

Thanks, it helped me! I know which not to buy!

Fantastic 👍🏻👍🏻👍🏻👍🏻👍🏻👏🏻👏🏻👏🏻👏🏻👏🏻⭐️⭐️⭐️⭐️⭐️